Cooling and lubricating system for sewing machines



Nov. 14, 1961 F. F. ZEIER ETAL CGOLING AND LUBRICATING SYSTEM FOR SEWING MACHINES 2 Sheets-Sheet 1 Filed Sept. 4, 1959 INVENTORS Frederick F. Zeier and Edwards Skowrons/r/ Nov. 14, 1961 F. F. ZEIER ETAL COOLING AND LUBRICATING SYSTEM FOR SEWING MACHINES 2 Sheets-Sheet 2 Filed Sept. 4, 1959 m S a 0 WWW 2 a 0 6 V .5 k mm .V... r a e w d r, 5 F 4 4 7 l 4 a m atent 3,%8,438 Patented Nov. 14, 1961 ice 3,008,438 COOLING AND LUBRICATING SYSTEM FOR SEWING MACHINES Frederick F. Zeier, Bridgeport, and Edward S. Skowrouski, Trumbull, Coma, assignors to The Singer Manufacturing Company, Elizabeth, NJ, a corporation of New Jersey Filed Sept. 4, 1959, Ser. No. 833,2EB 3 Claims. (Cl. 112256) This invention relates to lubricating systems for sewing machines, and more particularly, to a lubricant circulating and cooling system therefor.

It is an object of this invention to provide a lubricating system for sewing machines capable of automatically circulating sufiicient lubricant not only to maintain the desired frictional characteristics at all of the bearing surfaces but also to provide a heat exchange medium for reducing the temperature of the sewing machine casing.

Another object of this invention is to provide a novel and eflective means for cooling the lubricant.

v With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations, and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

' FIG. 1 represents a perspective view of a sewing machine complete with supporting table and thread stand to which the lubricating system of this invention is applied,

FIG. 2 represents a top plan view of the lubricant reservoir and pump unit of this invention with the pump unit and a portion of the reservoir illustrated in horizontal cross section,

FIG. 3 is a cross-sectional view taken substantially along line 33 of FIG. 2 illustrating the pressure relief valve means associated with the pump unit, and

FIG. 4 is a vertical cross-sectional view of the reservoir and pump unit taken substantially along line 4-4 of FIG. 2.

Referring to FIG. 1 of the drawings, 11 indicates a feed-off-the-arm sewing machine carried on a table top 12 supported above the floor on a column 13. Supported beneath the table top at the opposite side of the column from the sewing machine is an electric power transmitter 14 fitted with a pulley 15 for driving the sewing machine by means of a belt 16, and with a pulley 17 engaging a belt 18 for driving a pulley 19 associated with a lubricant pump unit indicated generally as 20.

' The transmitter is preferably of that known type in which the electric motor operates continuously and the pulleys 15 and 17 may be drivingly connected or separated from the motor at the will of the operator as by a a friction clutch device or the like. The lubricant pump 20 will thus be operated simultaneously with the sewing machine 11.

The feed-ofi-the-arm sewing machine 11 includes a bracket arm 31 terminating in a sewing head 32 in which operating mechanism such as a needle bar 33 and the presser bar 3 4 are journaled. The sewing head 32 also provides a sump 32 for collection of lubricant delivered to bearings in the bracket arm. Extending transversely beneath the sewing head 32. is a free ended work sup porting arm 35 about which opposite sides of garment panels may be folded to form tubular articles such as sleeves and trouser legs, etc. The base 36 of the work supporting arm provides a sump 36 for collection of lubricant delivered to bearings in all of the sewing machine except the bracket arm.

Preferably, as is known in sewing machines of this type, plumbing is provided for directing lubricant from a single inlet 37 to all of the bearings requiring lubrication within the sewing machine. Similarly, piping is provided from an outlet 38 to the lubricant collecting sump in the sewing head 32 and from an outlet 39 to the lubricant collecting sump in the base 86 of the work supporting arm. The plumbing internally of the sewing machine is not illustrated in the drawings because this type of plumbing may be of the type which is known in the art in lubricating systems which are arranged completely within the sewing machine casing. These prior systems are primarily concerned with the circulation of lubricant for antifriction purposes Whereas in the system of the present invention, an important cooling function is also provided.

The pump unit 20, best illustrated in FIGS. 2 and 4, preferably comprises three separate positive displacement gear pumps provided by three pairs of meshing pinions 40, 41, and 42.

One of each of the pairs of meshing pinions 40, 41, and 42 is fast on a drive shaft 43 which carries the pump driving pulley 19. The other one of each of the pairs of meshing pinions is carried on a stub shaft 44. Each of the pairs of meshing pinions is provided with a pump housing 45 preferably provided by a pair of die cast plates formed with a chamber 46 for the gears and with an inlet conduit 47 and an outlet conduit 48. The pump housings 45 are separated by partitions 49 and end cover plates 59 complete the pump unit.

The inlet conduits 47 of the pumps provided by the meshing pinions 41 and 42 are connected by flexible tubes 61 and 62 to the outlets 38 and 39, respectively, leading from the surnps in the sewing head and in the base of the work supporting arm. The pump unit 20' is secured by bolts 63 to one side of a lubricant reservoir 64 adapted to be secured beneath the table top 12. Ports 65 and 66 formed in the reservoir side wall lead from the outlet conduits 48 of the pumps provided by the meshing pinions 41 and 42, respectively, to the interior of the reservoir above an inclined screen 67 carried therein.

A port 68, in the reservoir side wall beneath the screen 67 leads to the inlet conduit 47 of the pump provided by the meshing pinions 40. The outlet conduit 48 from the pinions 40 leads into a passageway 69 formed in a relief valve body 70 secured on the pump unit 20. As best illustrated in FIG. 3, the passageway 69 in the valve body is in communication with a valve outlet port 71 connected by a flexible tube 72 to a lubricant cooler which will be described hereinbelow. The passageway 69 also communicates with a valve seat 73 into which a piston 74 sets under the influence of a spring 75 of which the pressure may be adjusted by the screw 76. When the pressure in the valve outlet port 71 increases sufliciently to overcome the relief valve spring 76, the valve piston 74 will be shifted from the valve seat 73 and lubricant will be by-passed through the valve seat 73, through an outlet 77, and through a flexible tube 78 connecting the outlet 77 to a port 79 in the side wall of the lubricant reservoir 64.

The lubricant reservoir 64 may be closed at the top by a cover plate 80 held in place by a bracket 81, however, the cover plate 80 does not seal the reservoir which remains upon to the atmosphere. A dipstick 82 extending through a tube 83 extending through the cover plate 80 and secured to the table top 12 provides a ready means for examining the level of lubricant in the reservoir.

Extending vertically upwardly from the table top 12 at the rear of the sewing machine 11 is a post of a thread stand including a cross arm 91 at the top from which thread spool holders 92 depend, and a cross arm 93 intermediate the thread spools and the table top and formed with thread guiding apertures 94 for directing thread from the spools on the spool holders 92 to the sewing machine.

Supported by clips 95 on the post 90 0f the thread stand is a lubricant cooling radiator comprising two loops of tubing 96 and 97 one at each side of the post 90. At the top of the thread stand each of the tubing loops is bent to overlie and follow horizontally the shape of one sewing thread for delivery of said thread to said sewing 7 machine operating mechanism, a lubricant cooling radiator including a loop of't'ubing secured to said thread stand. and extending along said standard and said cross port 37 supplying lubricant to all the bearing surfaces of the sewing machine.

The pump unit 20, thus provides threedistinct pumps acting in concert, the pumps provided by meshing pinions 41 and 42 serving to draw lubricant from the sewing head 32 and work supporting arm 36 sumps, respectively, and to discharge the lubricant into the reservoir 64. The pump provided by the meshing pinions 40 serves to force lubricant from the reservoir 64 through the cooling loops 96 and 97 in seriatim and deliver the cooled lubricant to the inlet 37 leading to the distributional plumbing in the sewing machine for supplying the bearings with lubricant. V

The reservoir 64, open to the atmosphere, is interposed between the pumps defined by pinions 41 and-42 and the pump defined, by pinions '40 so that the pressure developed by pumping lubricant out of the sewing machine and that developed by pumping the lubricant back into the sewing machine will not be cumulative. V

The relief valve 70 at the discharge, of the pump defined by pinions 40 for delivering oil to thecooling loops and the sewing machine, thus, effects a positive control of the pressure of the lubricant delivered. In, practice,

satisfactory results have been obtained by adjusting the relief valve to maintain the pressure at approximately 7 pounds per square inch together with a selection of pulley sizes 17 and 19 to provide a flow of lubricant of approximately half a gallon per minute. With these temperature with an ambient temperature of 90 F.

The arrangement of the loops 96 and 97 of the cooling tubes along the thread stand post and cross arms, pro- 'vides an advantageous arrangement in which the loops are inconspicuous, unobstrusive, and positioned to take best advantageof any movement of air in the room to aid in the cooling of the lubricant.

Having thus set forth the nature of this invention,

what we claim herein is: a l. A sewing machine having a casing, operating mech anism in said casing, means for distributing lubricant to said operating mechanism, and a sump in said casing for collecting said lubricant, a lubricant pump unit having an arm thereof, and means for interposing said 'radiator in i one of said conduit means. r 2. A sewing machine having ,a casing, operating mechanism in said casing, means for distributing lubricantto said operating mechanism, and a sumpin said casing for collecting said lubricant, a lubricant pump unit having an inlet and an outlet, conduit means operatively connecting said pump unit outlet to said sewing machine lubricant distributing means and said pump unit inlet to said sewing machine sump, a sewing machine supporting table, a thread stand carriedonsaid table in spaced relation to said sewing machine, said thread stand including a substantially vertical standard rising from said't able' and cross arm carried on said standard above said sewing 7 machine and adapted to support a spool of'sewing thread for delivery of said thread to said sewing machine operating mechanism, a lubricant cooling radiator including a pair of tubing loops each secured 'to'said thread stand and extending each along said standard and over said cross arm thereof, means for connecting said tubing loops 'for passage of lubricant in seriatim therethrough, and

means for interposing said interconnected tubing loops' in said conduitrmeans interconnecting said pump unit outlet to said sewing machine lubricant distributing 3. A sewing machine having a casing, operating mechanism in said casing, means'for distributing lubricant to said operating mechanism, and a plurality of sumps in said casing for collecting saidlubricant, a sewing machine supporting table, a lubricant pump unit carried. on said values, it has been found that the temperature of the sewing machine casing may be maintained below body inlet and an outlet, conduit means operatively connecting said pump unit outlet to said sewing machine lubricant distributing means and said pump uni-t inlet to said sew- V iug machine sump, a sewing machine supporting table, a thread stand carried on said table in spaced relation to said sewing machine, said thread stand including a substantially vertical standard rising from said table and a cross arm on said standard adapted to support a spool of supporting table in spaced relation to said sewing macl1ine,fla reservoir open to the atmosphere associated with said pump unit, pump means associated'with said pump unit for drawing lubricant from; said. sewing machine sumps into said reservoir, pump means associated'with said pump unit for. delivering lubricant under pressure from said reservoir, means .associated' with said last men tioned pump means for controlling the pressure ofthe lubricant delivered from said reservoir, athread stand .carried on said sewing machine supporting table in spaced relation tosaid'sewing'machine and'including a substantially vertical standardrising from said supporting table and a cross arm on said standard adapted to support a thread spool for delivery of said thread to said sewing machine operating mechanism, a lubricant cooling radiator including a loop of tubing secured to said thread stand and extending along said standard ,and said cross arm thereof, and conduit means for connecting said lubri-' cant radiator between said last mentioned pump means and said means for distributing lubricant to said sewing machine operating mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 1,350,729 Kiewicz Aug. 24, 1920 2,447,115 Christensen Aug. 17, 1948 2,837,173 Ciecior' ;;s June 3, 1958 FOREIGN PATENTS 698,010

' Great Britain Oct. 7, 's 

